Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 81581 found under Bearing Ball Annular by Dressta North America Ltd. The National Stock Number assigned to this part is 3110004392579, and the Federal Supply Class is 3110 Bearings Antifriction Unmounted. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 81581.